The present invention generally relates to the field of probiotic micro-organisms, in particular to the field of non-replicating probiotic micro-organisms. Embodiments of the present invention relate to compositions comprising probiotic micro-organisms that were rendered non-replicating by extrusion. Such compositions may be used to treat or prevent disorders that are related to a compromised immune defense.
Probiotics may be defined as “Live microorganisms which when administered in adequate amounts confer a health benefit on the host” [FAO/WHO (2001) Health and Nutritional Properties of Probiotics in Food including Powder Milk with Live Lactic Acid Bacteria. Report of a Joint FAO/WHO Expert Consultation on Evaluation of Health and Nutritional Properties of Probiotics in Food Including Powder Milk with Live Lactic Acid Bacteria]. Therefore, the vast majority of published literature deals with living probiotics. However, several studies investigated the health benefits delivered by non-replicating bacteria but came to the conclusion that heat-inactivation of probiotics generally leads to a loss of their purported health benefit (Rachmilewitz, D., K. et al, 2004, Gastroenterology 126:520-528; Castagliuolo, I., et al., 2005, FEMS Immunol. Med. Microbiol. 43:197-204; Gill, H. S. and K. J. Rutherfurd. 2001, Br. J. Nutr. 86:285-289; Kaila, M., et al.,. 1995, Arch. Dis. Child 72:51-53; Wagner, R. D., et al., 2000, J. Food Prot. 63:638-644).
Some studies, however, showed that killed probiotics may retain some health effects. This may depend for example on the method used to inactivate them (Rachmilewitz, D., K. et al, 2004, Gastroenterology 126:520-528; Gill, H. S. and K. J. Rutherfurd. 2001, Br. J. Nutr. 86:285-289). The technologies used in the literature to kill probiotic strains are mostly heat-treatment, γ-irradiation, UV-treatment or chemical agents (formalin, paraformaldehyde).
Being able to use non-replicating probiotics in food products would have several significant advantages. As providing food products with viable probiotics also after longer storing times is not a trivial task, the possibility to use non-replicating probiotics would eliminate any problems associated therewith.
Further, the range of products that could be supplemented with probiotics and the associated health benefits could be broadened significantly.
To be applicable to the food industry, however, the method used to render probiotics non-replicating must be applicable in an industrial scale. γ-irradiation, UV-treatment or the use of chemical agents might be problematic in this respect. Even heat treatments might not be easy to apply for some product categories.
Further, it would be desirable if the non replicating probiotic micro-organisms did not only retain a small part of their health effects but retained substantial parts or all of their health effects compared to their viable counterparts.